Martin McGuinness says he believes many people want to come forward to be part of a legal process relating to child abuse in Northern Ireland. Photograph: Paul McErlane for the Guardian

An inquiry will be held into the history of child abuse inside institutions in Northern Ireland, the executive said today; it will report to the assembly before July.

Deputy first minister Martin McGuinness said he believed many wanted to come forward to be part of a legal process that "will in the time ahead hopefully give closure to people who for many decades felt they were not worthy or listened to.

"We believe that they are worthy, and entitled to be listened to and be treated as first class citizens."

The move follows pressure from victims to have a process similar to last year's Ryan report in the republic.

The Ryan commission revealed a catalogue of physical, sexual and emotional abuse in Ireland by priests and nuns as well as attempts to cover up the truth and move offenders between parishes.

Northern Ireland victims have met the office of the first minister and deputy first minister to seek a similar process.

First minister Peter Robinson said he did not envisage an inquiry of the scale of Bloody Sunday.

"If it is an inquiry that is more investigative, which can be done with fewer personnel then it is very much a smaller figure," he said.

Contact has been made with the police. Civil servants will represent the nine departments involved but they can seek specialist expertise.